Dart Requires Chilkat v11.0.0+
Dart
Signed Zip as Base64 with XAdES-BES
See more XAdES Examples
This example is to help companies implement a solution for sending XAdES-BES to the Polish government for reporting purposes. Specifically:Przed podpisaniem deklaracja zbiorcza (PIT-11Z, PIT-8CZ, PIT-40Z, PIT-RZ) musi zostać
umieszczona w archiwum ZIP. W tym przypadku, podpisywany jest plik archiwum ZIP,
przyjmujący w podpisie XAdES-BES formę zakodowaną base64.
The example demonstrates the following:
- Zip an XML file (PIT-11Z.xml is zipped to PIT-11Z.zip)
- Create XML to be signed, where the XML contains the base64 encoded content of the PIT-11Z.zip archive.
- XAdES-BES sign the XML containing the base64 zip.
This example will also show the reverse:
- Verify the signed XML.
- Extract the PIT-11z.zip from the signed XML.
- Unzip the PIT-11Z.zip to get the original PIT-11Z.xml
Chilkat Dart Downloads
import 'package:chilkat/chilkat.dart';
void main() {
// This example assumes the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.
// Zip the PIT-11Z.xml to create PIT-11Z.zip (not as a .zip file, but in-memory).
final sbXmlToZip = CkStringBuilder();
try {
sbXmlToZip.loadFile('qa_data/xml/PIT-11Z.xml', 'utf-8');
} on ChilkatException {
print('Failed to load the XML to be zipped.');
return;
}
final zip = CkZip();
// Initialize the zip object. No file is created in this call.
// It should always return true.
zip.newZip('PIT-11Z.zip');
// Add the XML to be zipped.
zip.addSb('PIT-11Z.xml', sbXmlToZip, 'utf-8');
// Write the zip to a BinData object.
final bdZip = CkBinData();
zip.writeBd(bdZip);
// The contents of the bdZip will be retrieved in base64 format when needed below..
final gen = CkXmlDSigGen();
gen.sigLocation = '';
gen.sigLocationMod = 0;
gen.sigId = 'Signature_2a8df7f8-b958-40cc-83f6-edb53b837347_19';
gen.sigNamespacePrefix = 'ds';
gen.sigNamespaceUri = 'http://www.w3.org/2000/09/xmldsig#';
gen.sigValueId = 'SignatureValue_2a8df7f8-b958-40cc-83f6-edb53b837347_52';
gen.signedInfoId = 'SignedInfo_2a8df7f8-b958-40cc-83f6-edb53b837347_41';
gen.signedInfoCanonAlg = 'C14N';
gen.signedInfoDigestMethod = 'sha1';
// Set the KeyInfoId before adding references..
gen.keyInfoId = 'KeyInfo_2a8df7f8-b958-40cc-83f6-edb53b837347_24';
// Create an Object to be added to the Signature.
final object1 = CkXml();
object1.tag = 'xades:QualifyingProperties';
object1.addAttribute('xmlns:xades', 'http://uri.etsi.org/01903/v1.3.2#');
object1.addAttribute('Id', 'QualifyingProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_43');
object1.addAttribute('Target', '#Signature_2a8df7f8-b958-40cc-83f6-edb53b837347_19');
object1.updateAttrAt('xades:SignedProperties', true, 'Id', 'SignedProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_4e');
object1.updateAttrAt('xades:SignedProperties|xades:SignedSignatureProperties', true, 'Id', 'SignedSignatureProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_0a');
// Chilkat will replace the strings "TO BE GENERATED BY CHILKAT" with actual values when the signature is created.
object1.updateChildContent('xades:SignedProperties|xades:SignedSignatureProperties|xades:SigningTime', 'TO BE GENERATED BY CHILKAT');
// Note: It may be that http://www.w3.org/2001/04/xmlenc#sha256 is needed in the following line instead of http://www.w3.org/2000/09/xmldsig#sha1
object1.updateAttrAt('xades:SignedProperties|xades:SignedSignatureProperties|xades:SigningCertificateV2|xades:Cert|xades:CertDigest|ds:DigestMethod', true, 'Algorithm', 'http://www.w3.org/2000/09/xmldsig#sha1');
object1.updateChildContent('xades:SignedProperties|xades:SignedSignatureProperties|xades:SigningCertificateV2|xades:Cert|xades:CertDigest|ds:DigestValue', 'TO BE GENERATED BY CHILKAT');
object1.updateChildContent('xades:SignedProperties|xades:SignedSignatureProperties|xades:SigningCertificateV2|xades:Cert|xades:IssuerSerialV2', 'TO BE GENERATED BY CHILKAT');
object1.updateAttrAt('xades:SignedProperties|xades:SignedDataObjectProperties', true, 'Id', 'SignedDataObjectProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_4b');
object1.updateAttrAt('xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat', true, 'ObjectReference', '#Reference1_2a8df7f8-b958-40cc-83f6-edb53b837347_27');
object1.updateChildContent('xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat|xades:Description', 'MIME-Version: 1.0\r\nContent-Type: application/zip\r\nContent-Transfer-Encoding: binary\r\nContent-Disposition: filename="PIT-11Z.zip"');
object1.updateAttrAt('xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat|xades:ObjectIdentifier|xades:Identifier', true, 'Qualifier', 'OIDAsURI');
object1.updateChildContent('xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat|xades:ObjectIdentifier|xades:Identifier', 'http://www.certum.pl/OIDAsURI/signedFile/1.2.616.1.113527.3.1.1.3.1');
object1.updateChildContent('xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat|xades:ObjectIdentifier|xades:Description', 'Opis formatu dokumentu oraz jego pelna nazwa');
object1.updateChildContent('xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat|xades:ObjectIdentifier|xades:DocumentationReferences|xades:DocumentationReference', 'http://www.certum.pl/OIDAsURI/signedFile.pdf');
object1.updateChildContent('xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat|xades:MimeType', 'application/zip');
object1.updateChildContent('xades:SignedProperties|xades:SignedDataObjectProperties|xades:CommitmentTypeIndication|xades:CommitmentTypeId|xades:Identifier', 'http://uri.etsi.org/01903/v1.2.2#ProofOfApproval');
object1.updateChildContent('xades:SignedProperties|xades:SignedDataObjectProperties|xades:CommitmentTypeIndication|xades:AllSignedDataObjects', '');
object1.updateAttrAt('xades:UnsignedProperties', true, 'Id', 'UnsignedProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_55');
// Emit XML in compact (single-line) format to avoid whitespace problems.
object1.emitCompact = true;
gen.addObject('', object1.getXml(), '', '');
// Create an Object to be added to the Signature.
// This is where we add the base64 representation of the PIT-11Z.zip
gen.addObject('Object1_2a8df7f8-b958-40cc-83f6-edb53b837347', bdZip.getEncoded('base64'), '', 'http://www.w3.org/2000/09/xmldsig#base64');
// -------- Reference 1 --------
gen.addObjectRef('Object1_2a8df7f8-b958-40cc-83f6-edb53b837347', 'sha1', 'C14N_WithComments', '', '');
gen.setRefIdAttr('Object1_2a8df7f8-b958-40cc-83f6-edb53b837347', 'Reference1_2a8df7f8-b958-40cc-83f6-edb53b837347_27');
// -------- Reference 2 --------
gen.addObjectRef('SignedProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_4e', 'sha1', '', '', 'http://uri.etsi.org/01903#SignedProperties');
gen.setRefIdAttr('SignedProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_4e', 'SignedProperties-Reference_2a8df7f8-b958-40cc-83f6-edb53b837347_28');
// Provide a certificate + private key. (PFX password is test123)
final cert = CkCert();
try {
cert.loadPfxFile('qa_data/pfx/cert_test123.pfx', 'test123');
} on ChilkatException catch (e) {
print(e.lastErrorText);
return;
}
gen.setX509Cert(cert, true);
gen.keyInfoType = 'X509Data';
gen.x509Type = 'Certificate';
// This will be an enveloping signature where the Signature element
// is the XML document root, the signed data is contained within Object
// tag(s) within the Signature.
// Therefore, pass an empty sbXml to CreateXmlDsigSb.
final sbXml = CkStringBuilder();
// The Polish government's XmlDSig implementation requires that we reproduce an attribute-sorting error.
// (This is an error in the XML canonicalization that is not noticed when both the signature-creation code and signature-verification code use
// the same XML canonicalization implementation w/ the bug.)
gen.behaviors = 'AttributeSortingBug,CompactSignedXml';
// Sign the XML...
try {
gen.createXmlDSigSb(sbXml);
} on ChilkatException catch (e) {
print(e.lastErrorText);
return;
}
// -----------------------------------------------
// Save the signed XML to a file.
sbXml.writeFile('qa_output/signedXml.xml', 'utf-8', false);
print(sbXml.getAsString());
// ----------------------------------------
// Verify the signature we just produced...
final verifier = CkXmlDSig();
try {
verifier.loadSignatureSb(sbXml);
} on ChilkatException catch (e) {
print(e.lastErrorText);
return;
}
try {
verifier.verifySignature(true);
} on ChilkatException catch (e) {
print(e.lastErrorText);
return;
}
print('This signature was successfully verified.');
// ------------------------------------
// Finally, let's extract the .zip from the signed XML, and then unzip the original PIT-11Z.xml from the in-memory zip.
final xml = CkXml();
xml.loadSb(sbXml, true);
// The base64 image of the PIT-11Z.zip is in the 2nd ds:Object child of the ds:Signature (the ds:Signature is the root element of the signed XML).
// (ds:Object[0] would be the 1st ds:Object child. Index 1 is the 2nd ds:Object child.)
final strZipBase64 = xml.getChildContent('ds:Object[1]');
bdZip.clear();
bdZip.appendEncoded(strZipBase64, 'base64');
if (bdZip.numBytes == 0) {
print('Something went wrong.. we dont\' have any data..');
return;
}
try {
zip.openBd(bdZip);
} on ChilkatException catch (e) {
print(e.lastErrorText);
return;
}
// Get the 1st file in the zip, which should be the PIT-11Z.xml
final entry = CkZipEntry();
try {
zip.entryAt(0, entry);
} on ChilkatException {
print('Zip contains no files...');
return;
}
// Get the XML:
final origXml = entry.unzipToString(0, 'utf-8');
print('Original XML extracted from base64 zip:');
print(origXml);
}